Images of the Week 2023

9 August 2023: In the constellation Sculptor lies this large extended spiral galaxy called NGC 289. Despite being around 75 million light-years away, the light of NGC 289 is stunningly captured here by the Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. The galaxy’s bluish arms reach through the expanse of space over 100,000 light-years, larger than the size of our own Milky Way. It’s classified as a Type II Seyfert galaxy with its ripe collections of star formation and bright core, but it’s also relatively faint. Studies have found that the galaxy contains large amounts of dark matter, which is a common feature of all galaxies with a low surface brightness. Dark matter is yet to be directly observed, which led the US Department of Energy to build the DECam in order to study the nature of dark …

2 August 2023: Beautiful sunsets often grace the telescopes of Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. Pictured in this aerial image are the Víctor M. Blanco 4-meter Telescope (foreground), the SMARTS 1.5-meter, 0.9-meter, and 1.0-meter Telescopes, the Curtis Schmidt Telescope, and many more of the 40+ NOIRLab-operated telescopes in the foothills of the Chilean Andes. At 2200 meters (7200 feet) above sea level and in its relatively isolated position, Cerro Tololo is the perfect place to observe the southern skies. In fact, the summit takes its name from the way it drops away steeply on the northern side, as described by the local Indigenous Diaguita people. After 60 years of fruitful discoveries, CTIO continues to push the boundaries of astronomy with bountiful observations of the abyss up above.

26 July 2023: In this panorama, the Milky Way galaxy curves over the summit of Maunakea in Hawai‘i like an arched gateway to the cosmos. The 8.1-meter Gemini North, one half of the International Gemini Observatory, operated by NSF NOIRLab, is visible at the center of the image, and the University of Hawaii 2.2-meter telescope is to its right. From atop the long-dormant volcano, in the dry air of the Pacific, Gemini North and its neighboring telescopes are superbly located for infrared observations. The infrared capabilities of Gemini North — and its twin telescope Gemini South in the southern hemisphere — allow astronomers to see through the cosmic dust that blocks visible light from stars and galaxies. They are also optimal for peering into the cold corners of the Universe. Gemini North has detected the potential first traces of the Universe’s earliest stars, confirmed the presence of an ultra-faint fossil galaxy, and detected …

19 July 2023: Underneath the clear blue sky of Cerro Pachón ridge in Chile, construction continues on Vera C. Rubin Observatory, a Program of NSF NOIRLab. The 8.4-meter telescope is equipped with a 3.2-gigapixel camera — the world’s largest digital camera ever fabricated for optical astronomy — and is expected to see first light at the end of 2024. It will conduct an unprecedented, decade-long survey of the optical sky called the Legacy Survey of Space and Time (LSST). This survey will aim to capture nearly 1000 images of the sky every night. The observations will detect 10 million changes in the sky per night and over the survey’s ten-year timeline they will produce a 15-petabyte catalog database. Dedicated computer facilities will process Rubin Observatory data in real time, issuing worldwide public alerts within 60 seconds of any detected changes in the sky. This massive amount of astronomical data will be a game-changing …

12 July 2023: In Saguaro National Park East just outside of Tucson, Arizona, Connie Walker collects data for Globe at Night — a citizen science project aimed at tracking and reporting the impact of light pollution on the visibility of the night sky. She and Steve Pompea, scientist emeritus at NSF NOIRLab, created the project in 2006, with an easy to use web-application. Over 17 years Globe at Night has gathered extensive data on stellar visibility through the collective efforts of over 250,000 people around the world. In January 2023 a paper was published in the journal Science that analyzed Globe at Night’s user-submitted data and found that skyglow is increasing more rapidly than indicated by satellite measurements of the Earth’s nighttime surface brightness. Globe at Night is one of the many activities that NOIRLab supports to protect the night sky. In February 2022, NSF NOIRLab and the SKA Observatory (SKAO), an intergovernmental …

5 July 2023: The Víctor M. Blanco 4-meter Telescope has pristine access to wide open skies of the Chilean Andes from its perch at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. To the upper left of the telescope is the ‘evening star’, actually the planet Venus. Below on the left are the SMARTS 1.5-meter Telescope and SMARTS 0.9-meter Telescope (furthest back). Housed within the silver dome of the Blanco Telescope is the Dark Energy Camera (DECam), mounted at the prime (first) focus near the top of the white Serrurier truss. The blue U-shaped structure holding the truss is the large bearing that sweeps the telescope around to a designated position for observing. DECam saw first light on 12 September 2012 and in its more than 10 years of operation it has contributed greatly to the field of astronomy. It was designed specifically for the Dark Energy Survey, operated by the …

28 June 2023: This image shows Gemini North, one half of the International Gemini Observatory, operated by NSF NOIRLab, using a yellow-colored laser beam to adjust its adaptive optics system during commissioning in 2016. This laser emanates from the middle of the telescope and travels through Earth’s atmosphere. It excites traces of sodium 90 kilometers (50 miles) up in Earth’s upper atmosphere so that the system can measure the atmospheric turbulence. The telescope’s individual instruments then use a system of deformable mirrors to compensate for the effect of the turbulence and achieve sharp images of stars, planets, and galaxies at resolutions that rival space-based instruments. The dim lights inside the dome, turned on during telescope operation, cast the dome interior in a red glow. Through the dome opening, you can see stars streaking across the sky — the result of the long exposure used to capture this photo. You can see another view …

21 June 2023: The shadowy clouds of LDN 1622 are pictured in this observation from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab. This image was captured in 2018 by the Mosaic-3 instrument, a wide-field camera used to capture large swaths of the night sky from Kitt Peak in Arizona. Mosaic-3 has since been retired to make way for the Dark Energy Spectroscopic Instrument (DESI), the most powerful multi-object survey spectrograph in the world. This swap highlights one of the benefits of ground-based astronomy: the ability to upgrade and replace instruments as new technologies become available. LDN 1622 is a dark nebula, so called because these dense interstellar clouds of gas and dust blot out light from background objects, appearing as ink-dark clouds against a backdrop of stars. This enigmatic cosmic cloud lies 1300 light-years from Earth in the nearby Orion complex, a star-forming …

14 June 2023: Below the southern skies, the telescopes of Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab, bask in the starlight of the brilliant Milky Way. Speckled with multi-colored stars, our home galaxy in this image stretches down into the city-lit horizon, just grazing past the Víctor M. Blanco 4-meter Telescope (left) and SMARTS 1.5-meter Telescope (right). The Small and Large Magellanic Clouds that accompany our home galaxy are seen to the left of the Blanco telescope. In between the telescopes blooms a deep shade of red that permeates through the tendrils of the Milky Way. This is the Gum Nebula, an emission nebula that blazes with the light of gas ionized by its host stars. From our perspective it holds a bountiful number of cosmic objects, from globular clusters, to the Vela Pulsar, and even to an 11,000-year-old supernova remnant. This photo was taken as part of the recent …

7 June 2023: The eighteen-story Nicholas U. Mayall 4-meter Telescope is located at Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, and is seen here against the backdrop of two celestial landmarks of the northern hemisphere: The constellation Ursa Major (the Great Bear), with its seven bright stars that make the Big Dipper, on the right side of Mayall and the North Star Polaris on the left. The stars of the Big Dipper asterism are notable even on their own. The second star in the Big Dipper’s handle is Mizar and together with its fainter companion star Alcor they are known as the Horse and Rider. Their pairing is a naked-eye double since they appear to observers to be right next to each other. Because of their close proximity, trying to resolve the pair with only the naked eye has been a traditional sight test in many countries. The stars Merak …

31 May 2023: A rainbow cloud creates a stunning curtain of colors just after sunrise in this image taken from Cerro Pachón in Chile, home of one half of the International Gemini Observatory, the SOAR Telescope, and Vera C. Rubin Observatory, all operated by NSF NOIRLab. The appearance of pastel pigmentation sweeping across the sky is possibly due to the phenomenon known as cloud iridescence. Similar to the swirling colors on the surface of a bubble or oil spill, this optical effect occurs when sunlight passes through a particularly thin cloud that is composed of water droplets or ice crystals of uniform size. As the Sun’s rays encounter individual crystals, the light is both diffracted and scattered, revealing a gradient of the component wavelengths, or colors, that make up the Sun’s light. Because of the smooth, wavy shape of the clouds in this image, they closely resemble a different class of iridescent clouds …

24 May 2023: Star trails blur and lasers streak across the sky in this long-exposure view from Pu‘u Poli‘ahu, the mountain peak adjacent to the Gemini North telescope of the International Gemini Observatory, operated by NSF NOIRLab. Gemini North can be seen slightly to the right of the center of this image, shooting its laser into the sky. A handful of other telescopes that are part of the Maunakea Observatories in Hawai‘i surround Gemini North. Despite resembling searchlights or a battle from a sci-fi film, the lasers in this image play a vital role in correcting the vision of Gemini and the other cutting-edge telescopes. They are part of these telescopes’ adaptive optics systems, and help astronomers measure the distortions in their data caused by atmospheric turbulence. By continuously feeding these measurements into computer-controlled deformable mirrors, astronomers can compensate for almost all of the blurring caused by Earth’s atmosphere. This provides Gemini North …

17 May 2023: NGC 1808 is a barred spiral galaxy located in the southern constellation Columba (the dove). This image was captured using the Dark Energy Camera (DECam), which is mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab, in Chile. The core of NGC 1808 is thought to house a supermassive black hole, characterized by its accretion of material and higher-than-normal brightness. The smoldering center is closely surrounded by a faint blue ring populated with star clusters and supernova remnants. This region is defined by its starburst activity, producing an exceptional number of hot, bright, young stars. The abundance of rapid star formation is thought to be the result of past tidal interactions with the nearby galaxy NGC 1792. Laced throughout this middle region of NGC 1808 are dark dust lanes resulting from large outflows of hydrogen gas from the galactic nucleus. …

10 May 2023: The dynamic coloring of the night sky at Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, makes for a beautiful backdrop behind the UArizona Bok 2.3-meter Telescope. Distant city lights, cars, airglow, and the arc of the Milky Way all add to the variety of colors. Zodiacal light emanating from the horizon intersects with the Milky Way on the right hand side of the image. One orange star at the center of this image stands out amongst the rest. This is the red supergiant Betelgeuse, a star that marks a ‘shoulder’ of the hunter constellation, Orion. Being a relatively old star, Betelgeuse glows a cool red compared to its hot, bright blue neighbors. Despite this, it is usually the 10th brightest star in the night sky. More compellingly, Betelgeuse is massive — so massive that its diameter is more than 750 times that as the Sun. This makes …

3 May 2023: Looking south across 100 kilometers (62 miles) of the Andean mountains in Chile, several telescopes dot the peaks on the horizon. On top of Cerro Pachón (center background), from left to right, are the Southern Astrophysical Research (SOAR) Telescope, the Gemini South telescope (one half of the International Gemini Observatory), and Vera C. Rubin Observatory. About 10 kilometers (6.2 miles) west is the mountain Cerro Tololo where the Víctor M. Blanco 4-meter Telescope sits (far right in the image). Both peaks have telescopes that are part of Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. This image was captured from the site of La Silla Observatory, operated by the European Southern Observatory (ESO). The North Chile is home to a plethora of observatories all making the most of the dry desert climate, cloudless skies, and low light pollution. You can find a the complementary view of the La …

26 April 2023: Above the peaks of Cerro Pachón lies a bridge made of stars, intangible yet visible to the naked eye. This beautiful arch, composed of the Milky Way with its network of nebulae and interstellar clouds, seemingly connects the Rubin Auxiliary Telescope (AuxTel) (left) with the upcoming Vera C. Rubin Observatory (right), a Program of NSF NOIRLab. Some spectacles of the Universe dot around the Milky Way, from the Magellanic Clouds (center bottom) to the crimson emission nebulae (upper left and bottom right) to the green and red airglow on the horizon. Although it is possible to catch a glimpse of these treasures elsewhere on Earth, only in remote locations such as the highly elevated Andes can one truly bask in all their splendor. Rubin Observatory is a joint initiative of the National Science Foundation (NSF) and the US Department of Energy (DOE). Once completed, Rubin will be operated jointly by …

19 April 2023: Observing the night sky has never been so delightful as with this image of LBN 867, the Raspberry Nebula. Captured here by the Nicholas U. Mayall 4-meter Telescope using the Mosaic-3 detector at Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, this nebula is located in the constellation Orion. LBN 867’s overall structure, though, is more like an onion than a raspberry: it hosts three different celestial objects in one! The characteristic red bloom of LBN 867 is an emission nebula. It glows as a result of the ionization of hydrogen gas by the light from the star HD 34989. From the center of the image, this main sequence star shines prominently, though it is about as bright as the planet Uranus as seen from Earth. The last object is hidden in plain sight. Notice the subtle bluish glow around HD 34989? This is the reflection nebula vdB …

12 April 2023: The silver dome of the Gemini North telescope, one half of the International Gemini Observatory, operated by NSF NOIRLab, catches the setting Sun, caught between the red-hued earth of the Maunakea volcano and an inky-blue sky. The scale of astronomical infrastructure can be difficult to grasp from images, particularly when telescopes are located in vast landscapes under wide skies. However, if you look closely the staircases winding up the side of Gemini North are visible — revealing the true size of this telescope. The dome of Gemini North — and that of its twin, Gemini South in Chile — is around 46 meters (150 feet) across, meaning that the two telescopes side-by-side would almost fit in an entire soccer field! This photo was taken as part of the recent NOIRLab 2022 Photo Expedition to all the NOIRLab sites.

5 April 2023: The McMath-Pierce Solar Telescope, located at Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab, is captured here beneath the full moon just after sunset. This is the perfect time of day to witness a phenomenon known as the anti-twilight arch, nicknamed the Belt of Venus. The belt forms directly opposite the rising or setting Sun — in this image, the Sun is setting in the west behind the camera. Rays of light from the Sun hit the eastern atmosphere at the antisolar point, the point directly opposite the sun from an observer’s perspective. The light is then backscattered off of the atmosphere and reflected back to the observer at a longer wavelength, changing the typically blue-appearing light into pink. The band of dark blue sky below the anti-twilight arch is actually the Earth’s shadow! You can find a diagram representation of this phenomenon here. This photo was taken …

28 March 2023: From the high altitude of Cerro Tololo Inter-American Observatory (CTIO) in Chile, two astrophotographers captured the elusive sunset phenomenon known as the green flash. This stunning trick of light occurs at sunset and sunrise when light from the Sun travels through the thickest part of Earth’s atmosphere. Acting like a prism, Earth's atmosphere bends, or refracts, the light and separates it into its component wavelengths. Blue and violet light are scattered by the atmosphere, while red, orange and yellow are refracted below the solar disk below the horizon, leaving the green light the most visible during the few seconds that the Sun disappears below the horizon. Here, though, is another uncommon phenomenon. Distinct thermal layers above the Pacific Ocean led to a Fata Morgana mirage displaying several green flashes. Two photographers from the recent NOIRLab 2022 Photo Expedition jointly worked the controls of the camera to quickly capture the elusive …